Intermittent freezing when streaming video

Windows 10 Home x64 21H1 ~ Intel Core2 Duo @ 2.2ghz ~ 6gb RAM ~ 1gb AMD Radeon HD 6570 graphics card ~ 30+mbs broadband ~ Firefox Quantum (latest) w/ RAM-only cache

OK now that you're all done laughing at my really, really old system, here's the thing: first, I'm not sure where the problem lies so if you think this belongs in a different forum please let me know. Second, this system works perfectly well for my needs, which are basic: surfing, email, documents, and streaming video in SD on Netflix and Hulu ~ no games.

The problem I'm having is strange to me: while watching a streaming SERIES episode, the picture freezes after approximately 45 minutes runtime. Audio continues over the still image, and I pause, count to three, jump back 10 seconds and the stream starts up again in sync and completes normally.

Here's the important oddity: this DOES NOT HAPPEN if I am watching a MOVIE, regardless of runtime. It only happens streaming SERIES episodes.

So, to make sure that's clear: if I watch a 120-minute movie on either service I have no problems and the screen never freezes at any point. If I watch a 50-minute TV show -- any show -- the freeze almost always occurs at around the same time: 45 mins in.

It's frustrating more than anything else, but I'd like to figure it out if possible. I have NO idea what might be the cause, or what difference there could possibly be in streaming mechanics between the two types which might explain it.

Any hints & allegations mightily appreciated! As ever more specs/details on request. THX